ggplot (continued)

Bar plots

## 
##   4   f   r 
## 103 106  25

### Using Colors

  1. Aesthetics
  1. Colors that are attractive - large geoms (fills) - pale colors - small geoms(lines,points) - bright colors
  2. Colors that highlight elements - pale, grey to de-emphasize - bright or saturated colors to emphasize
  3. Colors that are visible to the color blind
  4. Colors that convert well to black and white
  1. Information content
  1. Discrete scale
  • colors to group similar treatments
  • neutral colors (black,grey,white) to indicate control groups
  • Symbolic colors (heat=red, cool = blue, photosynthesis/growth=green, oligotrophic=blue, eutrophic=brown, infected=red)
  • Colors that map to chemical stains or gels, or even colors of organisms
  1. Continuous scale
  • monochromatic (differing shades of 1 color)
  • 2 tone chromatic scale (from color x to color y)
  • 3 tone divergent scale (from color x through color y to color z)
  1. Use color information within and between graphs
  1. show color names, hex in base R
  2. show color schemes in colorbrewer

using alpha transparency for histograms

## 'data.frame':    200 obs. of  2 variables:
##  $ v1 : num  -0.0306 1.4022 0.166 2.5987 -1.1781 ...
##  $ lab: Factor w/ 2 levels "Control","Treatment": 1 1 1 1 1 1 1 1 1 1 ...